The Late Henry Moss (2000) If, in entering San Francisco's 740-seat Theatre on the Square, the usual warnings about ''confiscation'' of cameras seem more severe, well, that is...The Late Henry Moss (2000)Sam Shepard If, in entering San Francisco's 740-seat Theatre on the Square, the usual warnings about ''confiscation'' of cameras seem more severe, well, that is...2000-12-15

If, in entering San Francisco’s 740-seat Theatre on the Square, the usual warnings about ”confiscation” of cameras seem more severe, well, that is Sean Penn on stage. Penn has been amusingly cast to combative type in the world premiere of Sam Shepard’s The Late Henry Moss, playing a wily brooder with a tendency to ”fly off the handle.”

Penn is pissed because, newly arrived at the New Mexico adobe where his monster of a father lies shrouded, he can’t get the locals to volunteer what they know about the patriarch’s last days. Not Woody Harrelson, hysterical as a cabdriver little aware that he’s stumbled onto one of Shepard’s all-time dysfunctional dynasties. Nor Cheech Marin, a meek neighbor whom Penn also terrorizes. And certainly not Nick Nolte, as Penn’s amiable elder brother, doing the latest in his line of sad, blustery men’s men overcompensating for childhood emasculations.

This adobe’s deep in Shepard country, so we expect ancient family secrets; the first act’s fraternal psychodrama has a been-there-unburied-that familiarity. But the surprise second- and third-act tonal shifts — from slapstick to X-Files spiritualism — are exhilarating. The ensemble is optimally balanced for Shepard’s zen equilibrium between angry siblings, baffled outsiders, and spirits in the night.

It’s James Gammon — playing the title corpse, a bad dad of nuclear proportions, in bellowing flashback — who’s the best reason to catch Henry, even if he’s not why tickets are going for hundreds online. (The sold-out five-week engagement ends Dec. 17.) Even before expiring, Gammon’s Moss is convinced he’s dead, thanks to strong drink, unforgivable sins, and the bizarre ministrations of a succubus. With apologies to Penn, Gammon is a dead man walking nonpareil. A-